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We describe a new stiletto snake, Atractaspis, from western Liberia and southeastern Guinea. The new species shares with morphologically similar western African Atractaspis species, A. reticulata and A. corpulenta, the fusion of the 2nd infralabial with the inframaxillary. From A. corpulenta the new species differs by a more slender body (276-288 ventrals and 19 or 20 dorsal scale rows versus 178-208 ventrals with 23-29 dorsal scale rows), a divided anal plate and divided subcaudal scales (both non-divided in A. corpulenta). The new species differs from most A. reticulata by having 19 or 20 dorsal scale rows at midbody (versus 21-23, rarely 19), and a lower ventral count (276-288 versus 304-370). The new species thus has a relatively longer tail: snout-vent-length / tail-length in the female holotype (15.7) and paratype (21.5) versus a mean of 23.6 in seven female A. reticulata. The new Atractaspis likely is endemic to the western part of the Upper Guinea forest zone and thus adds to the uniqueness of this diverse and threatened biogeographic region. [ABSTRACT FROM AUTHOR]

Members of the snake subfamily Aparallactinae occur in various habitats throughout sub-Saharan Africa. The monophyly of aparallactine snakes is well established, but relationships within the subfamily are poorly known. We sampled 158 individuals from six of eight aparallactine genera in sub-Saharan Africa. We employed concatenated gene-tree analyses, divergence dating approaches, and ancestral-area reconstructions to infer phylogenies and biogeographic patterns with a multi-locus data set consisting of three mitochondrial ( 16S , cyt b, and ND4 ) and two nuclear genes ( c-mos and RAG1 ). As a result, we uncover several cryptic lineages and elevate a lineage of Polemon to full species status. Diversification occurred predominantly during the Miocene, with a few speciation events occurring subsequently in the Pliocene and Pleistocene. Biogeographic analyses suggested that the Zambezian biogeographic region, comprising grasslands and woodlands, facilitated radiations, vicariance, and dispersal for many aparallactines. Moreover, the geographic distributions of many forest species were fragmented during xeric and cooler conditions, which likely led to diversification events. Biogeographic patterns of aparallactine snakes are consistent with previous studies of other sub-Saharan herpetofauna. [ABSTRACT FROM AUTHOR]